RESUMO
A sky scanner was developed that collects spectral radiance data over the wavelength range 390-1732 nm by use of two radiometers, the first being a monochromator with a 512-element silicon diode array and the second being a near-infrared acousto-optic tunable filter (AOTF) coupled to an InGaAs detector. The scanner is capable of completing a set of spectral radiance measurements at 146 points in the sky hemisphere in a period of less than 4 min.
RESUMO
In 1988 the New Zealand Department of Scientific and Industrial Research initiated a program to characterize the spectrum of solar ultraviolet radiation reaching the ground in New Zealand and to identify the extent and causes of its variability. Routine measurements began at Lauder (45 degrees S 170 degrees E) in December 1989. The instrumentation, measurement strategy, and calibration procedures are discussed and uncertainties in the measurements are analyzed. With the present system useful measurements at 1-nm resolution are limited to irradiances greater than 10(-3) microW cm(-2) nm(-1), which corresponds to a lower limit in wavelength in the region 290-295 nm (depending on the Sun angle and ozone amount). This is a useful lower limit for many applications of relevance to the biosphere. Results from the first year of operation are presented and discussed.
